Difference in deflections of a simple beam under a moving load

[bennuDJ]

Hello everyone,

I'm new to OpeenSeesPy and haven't mastered the platform's capabilities yet, so don't blame me if I've made some beginner mistakes.

I tried to analyze a simple beam under a single moving force, which moves at a constant speed of v=100km/h (see Fig. 1).

https://imgur.com/2zXjl5j

The problem is that the solution (vertical mid-span displacements) differs from what I get through an analytical solution (see Fig. 2) to the equation of motion, given the same input parameters.

https://imgur.com/SL8KsjS

I am attaching the code I used and graphs (see Fig. 3 - OSP & Fig. 4 - analitical) of the results I got from OpeenSeesPy and the analytical solution.

https://imgur.com/Wwq8uoJ

https://imgur.com/MjR0uiy

I kindly ask for your help and suggestions, for which I am grateful in advance!

Best regards!

[bennuDJ]

I solved the problem by changing (decrease) the step dt in the analysis and removing the Rayleigh damping factors for nodes & elements.

So now the same results were obtained.